To reduce local air pollution, many ports in developed countries require berthed ships to use shore-based electricity instead of burning diesel to meet their electricity requirement for loads such as lights, cargo-handling equipment, and air conditioning. The benefits of this strategy in developing countries remain understudied. Based on government data for all major ports in India, we find that switching from high-sulfur fuel to shore power reduces hoteling emissions of particulate matter (PM_2.5) by 88%; SO₂ by 39%; NO _x by 85%; but increases CO₂ emissions by 12%. Switching from low-sulfur fuel reduces hoteling emissions of PM_2.5 by 46% and NO _x by 84% but increases SO₂ emissions by 240% and CO₂ emissions by 17%. The lifetime cost savings from the switch to electricity are $73 M for high-sulfur fuel and $370 M for low-sulfur fuel. We estimate that switching from high-sulfur fuel to shore power might avoid at most a couple of dozen premature deaths each year, whereas switching from low-sulfur fuel could lead to a slight increase in premature mortality. Therefore, policymakers must first clean up power generation for shore power to be a viable strategy to improve air quality in Indian port cities.